teams_mark_read · Teams MCP Server MCP: Risk & Policy

WHAT IT DOES

What teams_mark_read does on Teams MCP Server

AI agents use teams_mark_read to create or update resources in Teams MCP Server — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Teams MCP Server environment.

WHY IT NEEDS A POLICY

Why teams_mark_read needs a policy

Marking messages as read is a write operation that modifies metadata about the user's interaction state with a conversation. It is reversible (messages can be marked unread), has no destructive consequences, and does not execute external code or trigger financial transactions. The low severity reflects that misuse would only affect notification/read state with minimal blast radius.

From the tool's definition The tool description states it 'updates your read position so messages up to (and including) the specified message are marked as read.' This is a reversible state change that modifies data (read status) without deletion or side effects.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

teams_mark_read Rate-limited

teams_mark_read stays usable, but capped — an agent stuck in a loop can't make hundreds of changes a minute. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "teams_mark_read": {
      "limits": [
        {
          "counter": "teams_mark_read_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

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Instant setup, no code required.

PolicyLayer is an MCP gateway: every tool call is checked against your rule before it reaches Teams MCP Server, so you can run agents against it safely.

FAQ

Questions about teams_mark_read

What does the teams_mark_read tool do? +

Mark a conversation as read up to a specific message. This updates your read position so messages up to (and including) the specified message are marked as read. It is categorised as a Write tool in the Teams MCP Server MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on teams_mark_read? +

Register the Teams MCP Server MCP server in PolicyLayer and add a rule for teams_mark_read: allow, deny, rate-limit, or require approval. Point your MCP client at the PolicyLayer proxy URL and the rule is enforced on every call, before it reaches Teams MCP Server. Nothing to install.

What risk level is teams_mark_read? +

teams_mark_read is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.

Can I rate-limit teams_mark_read? +

Yes. Add a rate_limit block to the teams_mark_read rule in your PolicyLayer policy. For example, setting max: 10 and window: 60 limits the tool to 10 calls per minute. Rate limits are tracked per agent session and reset automatically.

How do I block teams_mark_read completely? +

Set action: deny in the PolicyLayer policy for teams_mark_read. The AI agent will receive a policy violation error and cannot call the tool. You can also include a reason field to explain why the tool is blocked.

What MCP server provides teams_mark_read? +

teams_mark_read is provided by the Teams MCP Server MCP server (m0nkmaster/msteams-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.